Answer
9 hm
Work Step by Step
We need to move the decimal point two places to the left. Therefore, we need to use a unit that is equal to 100 m and this unit is $hm$ (hectometer). We know that 1 hm = 100 m. We can convert 900 m to units of hm.
$900~m = \frac{900~m}{1}\times \frac{1~hm}{100~m} = 9~hm$
